Tension device for sewing-machines



(No Model.) B. O. BEDELL.

TENS ION DEVICE FOR SEWING MACHINES- 7 No. 359,420. I Patented Mar. 15,1887.

N. pnzns, Photo-Lithographer, wmin m n a UNIT D STATES PA'rnNr UFFICE.

BYRON G. BEDELL, OF PORT HURON, MICHIGAN.

TENSION DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No.359,420, dated March 15,1887.

Application filed July 1, 1886. Serial No. 206,788. (No model.)

To all whom it may concern:

Be it known that I, BYRON O. BEDELL, of Port Huron, in the county of St.Clair and State of Michigan, have invented new and useful Improvementsin Attachments to Sewing-llIachines; and I do hereby declare that thefollowing is afull, clear, and exact description thereof, referencebeing had to the accompanying drawings, which form a part of thisspecification.

This invention relates to certain new and useful improvements inattachments to sewing-maehines.

As my invention is especially applicable to that class of machineswherein the tension of the upper thread is controlled and regulated bythe compression of the thread between two disks upon the machine-head, Ishow and describe my improvement in connection therewith.

It is a well-known fact that after having run up a seam and it isdesired to remove the work the presser-foot has to be raised and a slackgiven to the thread by pulling upon it before removing the work;otherwise in pulling the work out with the tension on the thread theneedle is often bent and has its point hooked by striking against thepresser-foot.

The object of my invention is to construct a device that will,immediately upon raising the presser-foot, release the tension upon thethread, so that the work can readily be removed without bringing anystrain upon the needle. v

To this end my invention consists in the peculiar construction andarrangement of the tension device, adapted to be operated by the leverof the presser-foot, all as more fully hereinafter described.

Figure l is a perspective view of the head of a sewing-machine providedwith my improved tension device. Fig. 2 is a cross-section on the line00 ac, Fig. 1. Fig. 3 is avertical section through a portion of thehead, showing the lever of presser-footin two posi-- tions. Fig. 4: is adetail perspective of the tension device.

In the'accompanying drawings, which form a part of this specification, Arepresents a sewing-machinehead, B its presser-foot, and O theneedle'bar. The resser-foot is raised by means of the cam-lever D, theseparts being arranged substantially alike in the various classes ofmachines now manufactured.

E is a stud tapped into the bottom of an enlarged recess, a, in thehead, and around the stud within the recessis placed a coil-spring, F.size, as shown, and threaded for a portion of its length. Over this endof the stud are slipped the two tension-disksG G, then a washer, H, andcoil-spring I, the whole being retained in place by the nut J. Thus farI have described one of the tension devices now in use, and the actionor operation of which is well known.

My particular improvement consists in boring a hole through thelongitudinal center of the stud E, which communicates with the slot binthe outer end of the stud. Across the central opening gin the washer H,I form a bridge, K, which latter, when the washer is in place, slipsinto the slot 2) and moves freely under the action of thetension-springs.

L is a headed pin, which I insert through the central bore of the stud,its inner end coming in contact with the bridge of the washer, while itsheaded end projects into the line of travel of the leverD when suchlever is raised or depressed to operate the prcsser-bar.

Referring to Fig. 2, it will be observed that the inner end of the leverD is upon one face beveled off, as at c, and the lever is shown in placeas in the position in dotted lines, Fig. 3, after having raised thepresser-foot. In this The outer end of this stud is decreased inposition the lever D, coming in contact with the I head of the pin L,pushes the latter forward, and it in turn, pushing the washer away fromthe disk G, necessarily releases such disk from the action of the springI, and hence the frictional tension on the thread between the disks isdestroyed, and the thread is free to be drawn through between them andthrough the needle without exerting any strain upon the latter. When thelever D is thrown down so as to lower the presser-bar, the head of thepin L slides down the beveled face of such lever, thus leaving-thespring I free to perform its functions in re-establishing the tensionupon the thread.

What I claim as my invention is slot, 1), spring F around said studwithin said recess, disks G G on said stud, the washer H, provided withbridge K, rcmovably engaging the slot 1) of the stud, spring I and nut Jon said stud, and the headed pin L, passed through said stud andengaging said bridge, substantially as described, andfor the purposesspecificd.

BY ON C. BEDELL. \Vitnesses:

H. S. SPRAGUE, CHAS. 'lnUmuN,

